Jay Rodriguez, right, has been a successful signing for West Brom and scored the winning goal against Manchester United at Old Trafford. Laurence Griffiths / Getty Images

Only one club has tasted victory at both Old Trafford and Anfield this season. It isn’t Manchester United or Liverpool, either. They are West Bromwich Albion and at some point – perhaps as soon as Sunday – their relegation will be ratified. After eight years in the Premier League, Albion will return to the Championship.

It will be one of the more ignominious demotions. It will also be one of the most inexplicable. Not in terms of the results – any team with only two wins in 32 attempts will be in trouble – but because of the context. Albion seemed configured to compete. As they have demonstrated in beating Liverpool, albeit in the FA Cup, and United, their best is comfortably good enough.

“I don’t know what their problem has been this season,” said the former West Brom striker Romelu Lukaku, even before Albion beat his United team.

Because Albion started the season seeming a model of stability. They had only posted fewer than 43 points once in this stint in the Premier League. They possessed a manager, in Tony Pulis, who had famously never been relegated and who signed a contract extension the day before the campaign began.

Albion oozed Premier League experience; some near the top of the table, much in dodging the drop. They had a battle-hardened group with a cadre of senior professionals who, until four of them stole a taxi during a mid-season break in Barcelona, seemed to offer the right sort of leadership.

Others still do. The good characters include goalkeeper Ben Foster, accomplished enough to surely attract offers from the Premier League, but who has already pledged to stay, and stand-in captain Chris Brunt, who has been eloquent in saying everyone involved must accept responsibility for their plight.

“With the squad of players we have got, we should be doing better,” the Northern Irishman said this week. Take a quartet who promised to form a solid square in the centre of the pitch. Jonny Evans has attracted interest from Arsenal and Manchester City in the last 12 months. Ahmed Hegazi was named in the team of the tournament in the Africa Cup of Nations. Grzegorz Krychowiak is a double Europa League winner. Gareth Barry holds the record for Premier League appearances.

This seemed risk-free recruitment, forming a strong-looking spine. There was even a success in the transfer market. Jay Rodriguez, a scorer at both Old Trafford and Anfield, has 11 goals and has delivered some stirring displays.

The Pulis formula of clean sheets and set-pieces scarcely set the pulse racing but Albion appeared grounded in reality; there were no delusions about an expansive style of play or finishing in the top six. They looked pragmatic role models.

Instead, as a blunt Brunt said: “We haven’t been good enough.” Rodriguez and Hegazi apart, the signings – Barry, Krychowiak, the injured Daniel Sturridge, the underused Oliver Burke – have been poor. Others have not played to their potential.

Albion’s squad – with barely a player under 27 – has seemed too old and tired. They have lost leads and an astonishing 26 points from winning positions. The caution that seemed common sense has been counter-productive: they have been draw specialists when they have really required wins.

"Pulis-ball" seemed efficient. There is no surprise Albion have had the second lowest share of possession or the third lowest number of shots on target. They are the joint lowest scorers.

The shock is in the league position and the points total. Because it is hard to explain why they went from continuity to catastrophe so abruptly.